[mr48chev]

Brand, that is a big can of worms as a lot of folks have their favorite brand of harness. I'll say that from all the feedback I get you want one with a stellar reputation for a good tech support system. Also one that has clearly marked wires and is said to have good instructions sheets.

I've spent too much time wedging my oversize bod under the dash to reach fuse panels and that quite often comes at inopportune times like when you are on a road trip and it is raining. The under the seat has a lot of appeal but that may cause a wire length issue. A buddy showed me his fuse block mounted on a slide down tray in his street rod a few years ago that made a lot of sense Hinged panel under the dash that hid the wiring if you got down and looked but with unlatching a latch the panel swung down and he could slde the fuse panel out several inches to reach it easily. He said he just left enough wire behind it to be able to pull it down without straining the wires. No photos because that was at a rod trot several years ago.